1. Field of the Invention
The present invention relates to a method for accurately quantifying a chemical substance contained in a sample solution at a significantly low concentration of not more than 1×10−8M.
2. Description of the Related Art
Japanese Patent Laid-Open Publication No. 2010-286423 discloses a method for quantifying a chemical substance contained in a sample solution by a potentiometric method. In the potentiometric method, a surface potential of a measurement electrode which varies with a chemical reaction is measured.